1. Field of the Invention
The present invention relates to a liquid crystal display device.
2. Background Art
In recent years, liquid crystal display devices are widely used as information display devices of mobile equipment. For miniaturizing the mobile equipment, liquid crystal display devices are required to reduce the entire thickness.
On the other hand, since liquid crystal display devices are not self-luminous, a planar lighting unit called a backlight is required in many cases. In the liquid crystal display device used for mobile equipment, a method has been known in which a light source is provided on the side face of a light guide plate as a planar lighting unit for reducing the thickness of a backlight. In such a planar lighting unit, an appropriate structure is provided for the light guide plate for uniformly scattering light introduced from the side face to the front face. In the planar lighting unit, it must be noted that unnecessary light should not reflect in the screen.
For example, JP-A-7-43710 discloses a liquid crystal display device in which a plurality of grooves having protrusions that protrude outwardly on both ends of an opening are provided on the surface of a light guide plate. In the liquid crystal display device, light incident on the protrusion exits outwardly, is irregularly reflected by a reflector, and then enters again the light guide plate.
Further, JP-A-2005-251687 discloses a liquid crystal display device in which a light source is provided on the side face of a light guide plate and a light shielding material is provided on a flexible printed circuit to prevent the color of the flexible printed circuit from being reflected in a screen.